Boil water and add 2 tsp. salt. Add soya chunks and allow it to cook for 30 minutes. This re-hydrates the soya chunks, making them soft and chewy. Drain the soya chunks and reserve 1 1/2 cups of water for the sauce. Squeeze out excess water from the chunks and set them aside. Heat oil in a sauce pan and add red chili flakes.
Add onions, bell peppers, green chillies, ginger and garlic. Fry till onions are soft and translucent. Add soya chunks to the onion mixture and season with salt. Toss to combine. Combine the reserved water with soy sauce, tomato puree and tomato ketchup. Add this mixture to the soya chunks and cook for 10 minutes until the sauce thickens.